Riyad-us-Saliheen 1397
'Abdullah bin 'Amr bin Al-'As (May Allah be pleased with them) reported: I heard the Messenger of Allah (PBUH) saying: "Whoever supplicates Allah to exalt my mention, Allah will exalt his mention ten times."
[Muslim]
Recitation of Salat upon the Prophet (PBUH) means the recitation of benediction. Such as the one recited in Salat "O Allah, have mercy on Muhammad...)" It is a prayer for mercy and exaltation of the Prophet (PBUH) which is highly meritorious. (At-Tirmidhi, Hadith Hasan).